Proper wound repair following injury, surgery, and disease is essential to maintaining a clear cornea and ultimately preserving vision. The long-term goal of this project is to understand the mechanisms involved in corneal wound repair. Two intriguing aspects of corneal wound repair are that the wound response varies dramatically between the wound area and the area adjacent to the wound, and that the type of wound affects both the epithelial and stromal healing responses. Our previous data suggest that transforming growth factor beta (TGF-[unreadable]) plays a critical role in the regulation of corneal wound repair. As part of our studies, we have found that the integrin aV[unreadable]6 is specifically upregulated in the wounded epithelium, and that thrombospondin- 1 (TSP-1) is upregulated in the stromal cells subjacent to the wound area. Both aV[unreadable]6 and TSP-1 activate TGF-[unreadable], which is normally present in an inactive latent form. The hypothesis that we propose to test is that corneal wounding stimulates the upregulation of aV[unreadable]6 in the epithelium and TSP-1 in the stromal cells leading to the local activation of TGF-[unreadable], resulting in inhibition of proliferation in the migrating epithelium and stimulation of proliferation and migration of the fibroblasts in the subjacent stroma. We propose three specific aims to examine the following questions: First, what is the effect of the total lack of TGF-[unreadable] signaling on wound healing? Second, what is the effect of altered TGF-[unreadable] activation through aV[unreadable]6 on the epithelium after wounding? Third, what is the effect of altered TGF-[unreadable] activation through TSP-1 in the stroma after wounding? In vivo and in vitro wound healing models of rats and mice will be used to examine these questions. Wound healing in mice lacking components of the TGF-[unreadable] signaling pathway, aV[unreadable]6 and TSP-1 will be examined to determine the function of these proteins in wound repair. In addition, specific inhibitors of TGF-[unreadable] signaling, aV[unreadable]6 and TSP-1 will be examined to determine their role in corneal wound repair. Wound healing processes to be examined include: cell proliferation, cell migration, basement membrane resynthesis, and myofibroblast generation. Relevance to public health - Wound repair is a basic and crucial property of all tissues including the cornea. Because of its exposed position at the surface of the eye, the cornea is at risk to a variety of wounds including those created during laser surgery to correct vision. Our studies will allow a comparison of wounds that heal with minimal complications vs. wounds that heal in a manner that can be vision threatening.